1. Field of the Invention
The present invention relates to an adapter, and more particularly to a needle-less syringe adapter that has superior hermetic characteristics to prevent backflow of liquid medicine and remainder of air and liquid medicine therein.
2. Description of Related Art
Needle syringes are common medical implements for injection liquid medicine into patients. However, the needle syringes are dangerous and need recycle procedure that increases the cost of medical treatment.
Therefore, a needle-less syringe has been developed and may be connected to an adapter that is mounted on a cannula. The needle-less syringe has low hazard and may be reused. Therefore, the needle-less syringe lowers the cost of medical treatment.
A conventional adapter for the needle-less syringe has considerable vacant space and undesirable hermetic characteristics so that appreciable amount of liquid medicine and air easily remain in the adapter after an injection procedure is implemented. When the adapter is connected to a needle-less syringe for another injection procedure, the aforementioned remaining liquid medicine and air have been injected into the patient's blood vessel by positive pressure difference between the adapter and the patient's inside. The patient's blood vessel is expanded inadvertently and causes pain. When and injection procedure is finished and the needle-less syringe is disconnected from the adapter, the blood and liquid medicine in the blood vessel flow reversely backwards into the inter space in the adapter due to the negative pressure. Therefore, the inadvertent expansion of vessel during the aforementioned injection procedure makes patients feel pain. The reverse flow of the blood and liquid medicine into the adapter repeatedly mixes new liquid medicine in subsequent injection procedures to lower the curative effect of the liquid medicine and probably cause drug allergy.
To overcome the shortcomings, the present invention provides a needle-less syringe adapter to mitigate or obviate the aforementioned problems.